The Major Facilitator Superfamily Transporter HAP12 Is Critical in Toxoplasma gondii Survival and Virulence.

As an important zoonotic pathogen, Toxoplasma gondii relies on a unique organelle known as the apicoplast, which has garnered significant attention as a potential drug target for anti-Toxoplasma therapy. To better understand the structure and function of the apicoplast, we previously constructed a membrane protein database of the apicoplast. During this process, we identified the major facilitator superfamily (MFS) transporter protein HAP12, which partially colocalizes with the apicoplast. Evolutionary analysis revealed that HAP12 is highly conserved across the Apicomplexa family and model organisms. HAP12 depletion impaired T. gondii invasion and survival but did not affect the stability of several key organelles, including the apicoplast. Moreover, depletion of HAP12 resulted in a characteristic delayed-death phenotype in the apicoplast. Mouse virulence assays confirmed that HAP12 is an essential protein for parasite survival. This study provides new insights into potential drug and vaccine targets for combating Toxoplasma infections.